The present invention concerns a sorting unit for sorting items supplied to the sorting unit in bulk, preferably paving bricks with rectangular basic shape.
The need for special sorting units arises in particular in connection with production facilities for cast paving bricks, where the cast items are subjected to finishing treatment before transporting to stock or to the end user. Under normal circumstances, such cast block bricks may be laid out on the casting board in formation where they may palletised relatively easily after drying without any sorting in advance.
Certain types of paving brick are, however, after hardening of the concrete are subjected to finishing treatment in the form of “rumbling”, where the bricks otherwise arrayed on the casting board are transferred to a cylindric rotating drum, and the bricks are applied a kind of mellowness in that they are bumping against each other during the tumbling/rolling, whereby the edges of the brick are slightly blurred, and the surface is imparted a special, slightly worn appearance.
After the above treatment, the said paving bricks will be led out from the drum and are subsequently found in bulk, i.e. in a pile without any special arrangement of the bricks. In some cases, one has subsequently performed palletising of the bricks which is a particularly costly work, as individual bricks are to be handled manually and be laid upon a pallet, inferring that the price for rumbled bricks arranged on pallets is considerably greater than for similar bricks delivered in bulk. The advantage of delivering the bricks on pallets is that these are more easily handled/laid out than if they are only delivered in bulk, where they e.g. are tilted off a lorry upon the ground in a pile, from which they are transported/handled manually to the final laying site.
The need for rumbled paving bricks of concrete laid on pallets before delivery is thus great, but until now the purchasers of said types of paving bricks have refrained from having these delivered in palletised condition to a greater extent due to the somewhat higher delivery price for said bricks. Furthermore, it is to be noted that for the producer/wholesaler of the paving bricks delivered in bulk, it may sometimes be difficult to determine the accurate number of bricks delivered in connection with orders of a given number of square meters when the brick are in bulk. On the part of the producer/provider it is also necessary to be able to deliver the paving bricks in palletised condition.
U.S. Pat. No. 3,866,739, Sikorski, discloses an apparatus for unscrambling containers, where a take away conveyor; a shunting bar converging toward said take away conveyor; means for conveying containers to and along the shunting bar toward the take away conveyor; means for vibrating the shunting bar to assure free flow movement of the containers from the bar onto the take away conveyor; and means on the bar for effecting spinning of the containers which contact the bar by being propelled there toward by said conveying means, and wherein said means for effecting spinning comprises a frictional cushioning strip attached to and providing a facing of substantial thickness along the bar. The cushioned bar is mounted as a deflector across the path of side by side progressive speed advancing conveyors to divert containers randomly placed thereon toward single file orientation on a maximum speed take away conveyor. Oscillation of the bar jogs the containers to prevent jamming.
U.S. Pat. No. 4,889,224, Denker, discloses a conveyor system, which receives products in random order at its inlet end and delivers product in a serial aligned order at its outlet end. The conveyor system comprises first and second endless belt conveyors, which are longitudinally aligned and positioned such that the product exiting the first conveyor is received on the second conveyor. The first conveyor is of a greater width than the second and at the location where they meet is a third endless belt conveyor moving in a direction perpendicular to the longitudinal flow direction of the other two. The machine that feeds products to the first conveyor is set at a desired product flow rate in terms of products-per-minute and the speed of the first conveyor is set to handle that capacity. The second belt is driven at a speed equal to or greater than the product-per-minute rate times the product length. As misaligned products flowing on the first conveyor are intercepted by the transversely positioned third conveyor, the products are rotated as they are urged onto the second conveyor so that the length dimension of the products is generally aligned with the second conveyor.